Google is the best bet!

Answering your questions : 1-) Yeas, you can buy a ticket in the site. Be prepared to face long lines. 2-) The most common is to use Dollar Bills.

Sorry for delay my bad but yes it is

Yes

Yes, its possible but we bought them at the museum. Its easy and not at all crowded (even during the Christmas). Egypt is currently not experiencing the crowd it is generally famous for. You can get entry tickets at all major attractions using cash/ VISA card with no hassle at all.

Creo que tienes que comprar en persona y tal vez en efectivo, dólares estadounidenses o euros solamente. Y esa es la medida de mi español gringo

There are plenty of antiquities and mummies to see. Many beautiful breathtaking statues. Section of Tutankhamen is still there. I did not use a guide and went there myself. I was fine. Took my own time reading and looking and taking pics/ videos. There is nice shop inside the museum to buy souvenirs.

Hi Jessy This is probably too late for you, but may be helpful to someone else. First, check your credit card to see if the charge went through. Second, if it did, you can try contacting the Egyptian Monuments via Twitter or Facebook (links on on the EMonuments page where you bought the ticket). Note the Egyptian Museum itself does not process the payments but Egyptian Monuments - a separate entity processes the payment. Third, if the charge did not go through, you can buy a ticket at the ticket window at the Museum. Bring cash. Why? At several of the sites we went to see in Cairo in early October one couldn't use credit cards at the attraction , e.g., Sharia Muizz L'Din Allah. And the wait isn't too long unless you arrive after several tour buses. We had to wait about 10 minutes to get tickets when we came.